According to the Third Generation Partnership Project (3GPP) specifications for wireless communication systems (Release 8 and later Releases), a Long Term Evolution (LTE) cellular radio communication system uses Orthogonal Frequency Division Multiple Access (OFDM) as a multiple access technique (called OFDMA) in the downlink (DL) from network nodes (evolved NodeBs, or eNodeBs) to user equipments (UEs) and Discrete Fourier Transform (DFT)-spread OFDM in the uplink (UL) from UEs to eNodeBs (eNBs). In an OFDMA communication system, a data stream to be transmitted is portioned among a number of narrowband subcarriers that are transmitted in parallel. In general, a Physical Resource Block (PRB) is a particular number of particular subcarriers used for a particular period of time. Different groups of subcarriers can be used at different times for different purposes and different users. The LTE specifications can be seen as an evolution of current wideband code division multiple access (WCDMA) system specifications. An LTE system is sometimes also called an Evolved Universal Terrestrial Radio Access (E-UTRA) communication system.
In an LTE network, UL load generation for testing and other purposes is performed by special equipment (which can be called an uplink load tool) that computes the load in the uplink. Current uplink load tools have a number of drawbacks, such as that the network operator does not have positive control over the uplink load but only a guess at the load. For example, the exact number of UL PRBs and the power per PRB are not controlled by the uplink load tool but by the Scheduler in the eNB. Another drawback is that load generation requires special equipment, and so existing UEs cannot be used for load generation.